Improvement in combined beam-compass and calipers



W. BURRQWS. Calipers, Gage and T rammel.

Patented Dec. 29,1868.-

N. PETERS, PHOTO-LITHOGRAPHER. WASHINGTON, D C.

a e. d luged l fitaiw' 1 game (ldff WILLIAM BURROWS, or NEW YORK, N. Y.

' Lawn Patent No. 85,430, dated December 29,- 1868.

The Schedule referred to in these Letters Patent and. making part of thesame.

To all whom it may concern Be it known that 1, WILLIAM Bunnows, of thecity, county, and Stateof New York, have invented a new and usefulCombined Calipers, Gauge, and lrammel, of which the following is a full,clear, and exact description, reference being bad to the accompanyingdrawing, forming part of this specification, and in which Figure 1represents a plan of my combined calipers, gauge, and trammel; andFigure 2, a partly sectional side view of the same.

Similar letters of reference indicate corresponding parts.

The object of this, my invention, is the production in the one device,or as combined with a common stock, of instruments of differentcharacter or use, thoughsuitable'for operation in connection, orconsecutively, in carpentry, Joiners and other work.

. My invention consists, first, in a combination, in the one instrument,of a calipers, gauge, and trammcl, operating Without removal, orabsolutely necessary removal, of the parts or devices requisite toestablish the function of either tool.

Referring to the accompanying drawing- A represents the straight stockor bar of the combined instrument. This stock may be of any'desiredlength, and preferably, or mainly so, ofa V-shape in its transversesection. I

Fitting said bar, so as to be capable, either one or both of them, of aneasy but close sliding action on or along said bar, so that they maybeset at any desired distance apart, and held in such position byset-screws, B, are heads,,O, which serve to carry the trams ortrammel-legs D, thatmay be screwed into said heads, so as v to bereadily removable therefrom.

'Ifdesired, also, the set-screws B may have a screwthread cut in them,to receive-the trams or trammellegs I), for the purpose of working orusing the legs from opposite faces of the bar.

So far as described, the instrument simply acts as a trammel or gauge,with one or both legs adjustable.

To give the instrument its caliper-function, or action, Iprovide theheads 0 with caliper-blades or arms, E, running through saidheads'transversely to and over the bar A, and held in position on saidbar by the setscrews B. Thus arranged, it will be seen that thecaliperblades orarms, in being adjusted to and from each other, alwaysoccupy the same parallel relationship, and thus secure the same extentof blade or arm-projection, whether the distance to which the blades orarms are spread apart, or away from each other, be small or and b b, toadapt them to measuring both inside and outside work, the bent portionsa a serving to measure bodies on the outside, while the bent portions bb answer to measure inside work, the stock or bar A, or sides of theheads 0, acting, in the performance of the latter work, as astraight-edge or guide on the end or outside of the body being measured,to keep the blades or arms from twisting, or projecting unequally withinthe cavity or space undermeasurement.

It is desirable that both the stock or bar A, and blades or arms E,should be divided, or marked into measuredspaces on their upper faces,to facilitate the adjustment to fixed distances of the heads Quarryingthe trams l) and arms E, or either; also to facilitate the projection tofixed distances of said arms or blades.

While the instrument may thus be made to perform its several functionsof trammel, gauge, and calipers, without, of necessity, removing anyparts or devices necessary to the performance of the functions of eithertool, every facility is afforded, either by unscrewing the trams orlegsD, or on sliding out of the heads 0 the blades E, for converting theinstrument into simply a a calipers, or exclusively'a gauge or trammel.

What is here-claimed, and' desired to be secured by Letters Patent, is

The combination, in the one instrument, with a stock or bar A and heads0 O, of the trams orlegs D, and

. transversely-adjustable caliper-blades or arms E, ar-

ranged to operate, essentially as and for the purpose or purposes hereinset forth.

WM. BURROWS.

Witnesses: w

A. LE Gnnno, A. KDTNIER.

